Tkinter: how to refresh a canvas without duplicates?

[stewart]

Fredrik Lundh wrote:

> the create methods add new objects to the canvas.  if you want
> to replace them, you can either get rid of the old objects (using
> delete(id) or even delete(ALL)) or you can modify the objects in
> place (itemconfig, coords).

thanks, that did the trick!

> if you need to rapidly redraw things in a Tkinter widget, the WCK is
> often a lot more efficient:
> 
>     http://www.effbot.org/zone/wck.htm

I've tried to install this, but when I run 'python setup.py install', it
complains that it "cannot find /usr/lib/python/2.3/config/Makefile".  Why
would this be?